Mec 34-J Diesel Guide

Part # 95325
December 2021
Serial Number Range
14100000 - Up
Service & Parts Manual
34-J Diesel
Art 5596

Page i 34-J Diesel - Service & Parts Manual
December 2021
Revision History
Date Reason for Update
May 2021 New Release
1401 S. Madera Avenue, Kerman, CA93630 USA
Toll Free: 1-877-632-5438
Phone: [phone]
Fax: [phone]
[email protected]
www.MECawp.com
MEC Aerial Work Platforms

Page ii 34-J Diesel - Service & Parts Manual
December 2021
Table of Contents
Chapter 1 - Service . . . . . . . . . . . . . 1
Service Introduction.................1
Section 1 - MEC Operator Policy .............2
MEC Operator Policy . . . . . . . . . . . . . . . . . . . 2
Section 2 - Safety Symbols & General Safety Tips . . . . . . . . 3
Safety Symbols & General Safety Tips . . . . . . . . . . . . . . 3
Section 3 - Specifications . . . . . . . . . . . . . . . 4
Specifications.....................4
Section 4 - Torque Specifications . . . . . . . . . . . . . 5
Bolt Torque Specification - American Standard . . . . . . . . . . . . 5
Bolt Torque Specification - Metric Standard . . . . . . . . . . . . . 6
Hydraulic Components Torque Table . . . . . . . . . . . . . . . 7
Section 5 - Boom Support . . . . . . . . . . . . . . . 8
BoomSupport.....................8
Section 6 - Hydraulic, Electrical & Total System . . . . . . . . . 9
Hydraulic, Electrical and Total System . . . . . . . . . . . . . . 9
Section 7 - Primary Machine Components. . . . . . . . . . . 10
Primary Machine Components . . . . . . . . . . . . . . . . 10
Section 8 - Emergency Systems and Procedures. . . . . . . . . 11
Emergency Systems and Procedures . . . . . . . . . . . . . . . 11
Auxiliary Power System & Test . . . . . . . . . . . . . . . . 12
Section 9 - Transporting and Lifting Instructions . . . . . . . . . 13
Lift and Support the Machine . . . . . . . . . . . . . . . . . 13
Transportation Instructions . . . . . . . . . . . . . . . . . 14
Driving or Winching onto or off of a Transport Vehicle. . . . . . . . . . . 15
Section 10 - Hydraulic System . . . . . . . . . . . . . . 18
Hydraulic System – General . . . . . . . . . . . . . . . . . 18
Hydraulic Roadmap . . . . . . . . . . . . . . . . . . . 19
HydraulicFluid.....................21
Hydraulic Pumps . . . . . . . . . . . . . . . . . . . . 23
Hydraulic Manifolds . . . . . . . . . . . . . . . . . . . 25
Adjusting Relief Valves . . . . . . . . . . . . . . . . . . 27
Wheel Motor Startup Procedure . . . . . . . . . . . . . . . . 28
General Cylinder Repair . . . . . . . . . . . . . . . . . . 29
Section 11 - Electrical System . . . . . . . . . . . . . . 32
Electrical System - General . . . . . . . . . . . . . . . . . 32
Batteries......................34

Page iii 34-J Diesel - Service & Parts Manual
December 2021
Battery Replacement . . . . . . . . . . . . . . . . . . . 36
Section 12 - Controls . . . . . . . . . . . . . . . . 37
LowerControls.....................37
Platform Controls ....................39
Section 13 - Sensors, Relays & Alarms . . . . . . . . . . . 41
Sensors......................41
Relays .......................43
Alarms.......................44
Section 14 - Deutsch Connectors . . . . . . . . . . . . . 45
Deutsch Connectors . . . . . . . . . . . . . . . . . . . 45
Section 15 - Continuity Checks. . . . . . . . . . . . . . 46
Continuity Checks . . . . . . . . . . . . . . . . . . . . 46
Section 16 - Control System . . . . . . . . . . . . . . 48
ControlSystem....................48
GP500 Calibration . . . . . . . . . . . . . . . . . . . . 49
GP500 Calibration Procedure . . . . . . . . . . . . . . . . . 50
Section 17 - Calibration Troubleshooting . . . . . . . . . . . 55
Failure Messages . . . . . . . . . . . . . . . . . . . . 55
Information Messages . . . . . . . . . . . . . . . . . . . 60
Overload Event Counter Reset . . . . . . . . . . . . . . . . 63
Section 18 - Mechanical Components . . . . . . . . . . . . 64
Mechanical Components . . . . . . . . . . . . . . . . . . 64
Nordlock Washers . . . . . . . . . . . . . . . . . . . . 65
Platform Removal & Installation . . . . . . . . . . . . . . . . 66
Platform Rotator . . . . . . . . . . . . . . . . . . . . 67
Jib Cylinder/Jib Components . . . . . . . . . . . . . . . . . 69
Platform Level Cylinder . . . . . . . . . . . . . . . . . . 72
Boom Extend Cylinder. . . . . . . . . . . . . . . . . . . 74
Boom Lift Cylinder/Boom Linkage . . . . . . . . . . . . . . . . 76
Main Boom Assembly . . . . . . . . . . . . . . . . . . . 79
Swing Bearing/Turntable Components . . . . . . . . . . . . . . 82
Drive Motors & Gear Hubs. . . . . . . . . . . . . . . . . . 87
Engine Maintenance . . . . . . . . . . . . . . . . . . . 89
Lubrication Points . . . . . . . . . . . . . . . . . . . . 92
Section 19 - Troubleshooting . . . . . . . . . . . . . . 93
General Troubleshooting Tips . . . . . . . . . . . . . . . . . 93
Electrical System Troubleshooting. . . . . . . . . . . . . . . . 94
GP500 Module.....................95
Terminal Block Module . . . . . . . . . . . . . . . . . . 96
GP440Module.....................97
EZ-Cal Scan Tools. . . . . . . . . . . . . . . . . . . . 98
Using The EZ-Cal With The Flow Charts . . . . . . . . . . . . . . 99
EZ-Cal Messages ................... 102

Page iv 34-J Diesel - Service & Parts Manual
December 2021
Can Bus Related Messages . . . . . . . . . . . . . . . . 103
Calibration Related Messages. . . . . . . . . . . . . . . . 104
Interlock Messages .................. 105
Other Messages . . . . . . . . . . . . . . . . . . . 107
Troubleshooting Chart . . . . . . . . . . . . . . . . . . 109
Section 20 - Schematics . . . . . . . . . . . . . . . 115
Electrical Schematic - Lower Schematic . . . . . . . . . . . . . .115
Electrical Schematic - Turntable . . . . . . . . . . . . . . . .116
Electrical Schematic - Upper Controls. . . . . . . . . . . . . . .117
Hydraulic Schematic . . . . . . . . . . . . . . . . . . .118
Main Manifold Valves . . . . . . . . . . . . . . . . . . .119
Chapter 2 - Parts . . . . . . . . . . . . . . 121
Parts Introduction .................121
Section 21 - Controls ................122
Upper Controls Box Without PPSS, Part 2 . . . . . . . . . . . . 124
Upper Controls Box With PPSS, Part 1 . . . . . . . . . . . . . 126
Upper Controls Box With PPSS, Part 2 . . . . . . . . . . . . . 128
LowerControls.................... 130
Section 22 - Platform . . . . . . . . . . . . . . . . 132
Platform Assembly, 6 Foot. . . . . . . . . . . . . . . . . 132
Section 23 - Elevating Assembly . . . . . . . . . . . . . 136
Jib Assembly, Part 1 . . . . . . . . . . . . . . . . . . 136
Jib Assembly, Part 2 . . . . . . . . . . . . . . . . . . 138
Platform Rotator Assembly . . . . . . . . . . . . . . . . 140
Boom Assembly . . . . . . . . . . . . . . . . . . . 142
Boom Assembly, Boom Extend Cylinder . . . . . . . . . . . . . 148
Base Boom Assembly . . . . . . . . . . . . . . . . . . 150
Boom Tip Assembly . . . . . . . . . . . . . . . . . . 152
Section 24 - Axles . . . . . . . . . . . . . . . . . 154
Front Axle Assembly . . . . . . . . . . . . . . . . . . 154
Section 25 - Hydraulics . . . . . . . . . . . . . . . . 156
Main Manifold Valves . . . . . . . . . . . . . . . . . . 156
Main Manifold Assembly . . . . . . . . . . . . . . . . . 158
Manifold Case Drain Assembly . . . . . . . . . . . . . . . 160
Auxiliary Manifold Valves . . . . . . . . . . . . . . . . . 162
Auxiliary Manifold Assembly . . . . . . . . . . . . . . . . 164
Danfoss Pump Assembly . . . . . . . . . . . . . . . . . 166
Auxiliary Pump Assembly . . . . . . . . . . . . . . . . . 168
Hydraulic Tank Assembly . . . . . . . . . . . . . . . . . 170
Charge Filter Assembly . . . . . . . . . . . . . . . . . 172
Telescope Cylinder Assembly . . . . . . . . . . . . . . . . 174
Lift Cylinder Assembly . . . . . . . . . . . . . . . . . . 176
Telescopic Cylinder Assembly. . . . . . . . . . . . . . . . 178

Page v 34-J Diesel - Service & Parts Manual
December 2021
Jib Cylinder Assembly . . . . . . . . . . . . . . . . . . 180
Level Cylinder Assembly . . . . . . . . . . . . . . . . . 182
Axle Lock Cylinder. . . . . . . . . . . . . . . . . . . 184
Fuel Tank Assembly . . . . . . . . . . . . . . . . . . 186
Boom Hose Routing, Interior . . . . . . . . . . . . . . . . 188
Boom Hose Routing, Exterior . . . . . . . . . . . . . . . . 190
Chassis Hose Routing, Top View . . . . . . . . . . . . . . . 192
Chassis Hose Routing, Bottom View . . . . . . . . . . . . . . 194
Chassis to Turret Hose Routing, Side View . . . . . . . . . . . . 196
Turret Hose Routing, Engine Side Only . . . . . . . . . . . . . 198
Turret Hose Routing, Engine to Interior . . . . . . . . . . . . . 200
Turret Hose Routing, Engine to Controls . . . . . . . . . . . . . 202
Turret Hose Routing, Interior View. . . . . . . . . . . . . . . 204
Turret Hose Routing, Control Side. . . . . . . . . . . . . . . 206
Section 26 - Base . . . . . . . . . . . . . . . . . 208
Chassis Assembly, Part 1 . . . . . . . . . . . . . . . . . 208
Chassis Assembly, Part 2 . . . . . . . . . . . . . . . . . 210
Chassis Assembly, Part 3 . . . . . . . . . . . . . . . . . 212
Engine Hood Assembly . . . . . . . . . . . . . . . . . 214
Engine Side, Hood Stop Assembly . . . . . . . . . . . . . . 216
Control Hood Assembly . . . . . . . . . . . . . . . . . 218
Control Side, Hood Stop Assembly . . . . . . . . . . . . . . 220
D1105 Engine Kit . . . . . . . . . . . . . . . . . . . 222
Exhaust Assembly . . . . . . . . . . . . . . . . . . . 230
Turret Assembly, Part 1 . . . . . . . . . . . . . . . . . 232
Turret Assembly, Part 2 . . . . . . . . . . . . . . . . . 234
Turret Assembly, Part 3 . . . . . . . . . . . . . . . . . 236
Turret Assembly, Part 4 . . . . . . . . . . . . . . . . . 238
Section 27 - Options. . . . . . . . . . . . . . . . . 240
Option, Cold Weather . . . . . . . . . . . . . . . . . . 240
Option, 3.5kW Generator . . . . . . . . . . . . . . . . . 242
Option, 3.5kW Generator Manifold Assembly . . . . . . . . . . . . 246
Option, Upper Control Box Cover . . . . . . . . . . . . . . . 248
Option, 7.5kW Generator Assembly . . . . . . . . . . . . . . 250
Option - 7.5kW Breaker Box . . . . . . . . . . . . . . . . 252
Option - Subassembly, 7.5kW Outlet Boxes MkII . . . . . . . . . . . 254
Option - 7.5kW Generator Manifold Assembly . . . . . . . . . . . 256
Option - Proactive Platform Safety System . . . . . . . . . . . . 258
Section 28 - Decals . . . . . . . . . . . . . . . . . 260
Decals...................... 260

Page 1 34-J Diesel - Service & Parts Manual
December 2021
Service Introduction
This Service section is designed to provide you, the customer, with the instructions needed to
properly maintain the MEC self-propelled aerial work platform. When used in conjunction with the
illustrated Parts section in this manual and the Operator’s Manual (provided separately), this manual
will assist you in making necessary adjustments and repairs, and identifying and ordering the correct
replacement parts.
All parts represented here are manufactured and supplied in accordance with MEC quality
standards. We recommend that you use genuine MEC parts to ensure proper operation and reliable
performance.
To obtain maximum benefits from your MEC Aerial Work Platforms, always follow the proper
operating and maintenance procedures. Only trained authorized personnel should be allowed to
operate or service this machine. Service personnel should read and study the Operator’s, and the
Service and Parts Manuals in order to gain a thorough understanding of the unit prior to making any
repairs.
Chapter 1 - Service

Page 2 34-J Diesel - Service & Parts Manual
December 2021
MEC Operator Policy
Note: The best method to protect yourself and others from injury or death is to use common sense.
If you are unsure of any operation, don’t start until you are satisfied that it is safe to proceed
and have discussed the situation with your supervisor.
Service personnel and machine operators must understand and comply with all warnings and
instructional decals on the body of the machine, at the ground controls, and platform control console.
MODIFICATIONS OF THIS MACHINE FROM THE ORIGINAL DESIGN AND
SPECIFICATIONS WITHOUT WRITTEN PERMISSION FROM MEC ARE
STRICTLY FORBIDDEN. A MODIFICATION MAY COMPROMISE THE
SAFETY OF THE MACHINE, SUBJECTING OPERATOR(S) TO SERIOUS
INJURY OR DEATH.
MEC’s policies and procedures demonstrate our commitment to Quality and our relentless ongoing
efforts towards Continuous Improvement, due to which product specifications are subject to change
without notice.
Any procedures not found within this manual must be evaluated by the individual to assure oneself
that they are “proper and safe.”
Your MEC Aerial Work Platform has been designed, built, and tested to provide many years of safe,
dependable service. Only trained, authorized personnel should be allowed to operate or service the
machine.
MEC, as manufacturer, has no direct control over machine application and operation. Proper safety
practices are the responsibility of the user and all operating personnel.
If there is a question on application and/or operation, contact MEC Aerial Work Platforms:
1401 S. Madera Avenue, Kerman, CA93630 USA
Toll Free: 1-877-632-5438
Phone: [phone]
Fax: [phone]
[email protected]
www.MECawp.com
MEC Aerial Work Platforms
MEC Operator Policy
Section 1 - MEC Operator Policy

Page 3 34-J Diesel - Service & Parts Manual
December 2021
Safety Symbols & General Safety Tips
MEC manuals and decals use symbols, colors and signal words to help you recognize important
safety, operation and maintenance information.
RED and the word DANGER – Indicates an imminently hazardous
situation which, if not avoided, will result in death or serious injury.
ORANGE and the word WARNING – Indicates a potentially hazardous
situation which, if not avoided, could result in death or serious injury.
YELLOW with alert symbol and the word CAUTION – Indicates a
potentially hazardous situation which, if not avoided, may result in minor
or moderate injury.
YELLOW without alert symbol and the word CAUTION – Indicates a
potentially hazardous situation which, if not avoided, may result in
property damage.
GREEN and the word NOTICE – Indicates operation or maintenance
information.
Regular inspection and constant maintenance is the key to efficient economical operation of your
aerial work platform. It will help to assure that your equipment will perform satisfactorily with a
minimum of service and repair.
The actual operating environment of the machine governs the inspection schedule. Correct lubrication
is an essential part of the preventative maintenance to minimize wear on working parts and ensure
against premature failure. By maintaining correct lubrication, the possibility of mechanical failure and
resulting downtime is reduced to a minimum.
Never leave hydraulic components or hoses open. They must be protected from contamination
(including rain) at all times.
Never open a hydraulic system when there are contaminants in the air.
Always clean the surrounding area before opening hydraulic systems.
Use only recommended lubricants. Improper lubricants or incompatible lubricants may be as
harmful as no lubrication.
Watch for makeshift “fixes” which can jeopardize safety as well as lead to more costly repair.
•
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•
•
•
Safety Symbols & General Safety Tips
Section 2 - Safety Symbols & General Safety Tips

Page 4 34-J Diesel - Service & Parts Manual
December 2021
Specifications
Work Height* 40 ft 12.2 m
Platform Height 34 ft 10.4 m
Maximum Drive Height Full Height
Maximum Outreach 26 ft 8 m
Turntable Swing 355° Non-Continuous
Jib Range Of Motion 135°
Platform Rotation 180° (90° Each Side)
Machine Weight** (Unloaded) 8,600 lb 3,900 kg
Lift Capacity 500 lb 227 kg
Maximum Occupants 2
Stowed Height 95 in 2.4 m
Overall Length 20 ft 6.1 m
Overall Width 92 in 2.34 m
Tailswing 12 in 0.3 m
Platform Details
Width 72 in 1.83 m
Depth 40 in 1 m
Entry 1 End Swing Gate
2 Slide Bar Entries
Turning Radius, Inside 6 ft 6 in 2 m
Ground Clearance 8 in 20 cm
Lift Speed 30 sec
Extend Speed 15 sec
Jib Lift Speed 15 sec
Drive Speed
(Proportional) Stowed 0-4.0 mph 0-6.4 km/h
Raised or Extended 0-0.5 mph 0-0.8 km/h
Gradeability Stowed, Downhill 40%/22°
Stowed, Uphill 40%/22°
Breakover Angle 40%/22°
Axle Oscillation 10° (5° Each Side)
Maximum Allowable Operating Wind
Speed 28 mph 12.5 m/sec (45 km/h)
Engine Kubota D1105 - Tier 4 Final
Fuel Type Diesel
Fuel Capacity 16 gal 60 liter
Hydraulic Fluid Capacity 26 gal 100 liter Sound Pressure At Workstation 80 dB(A)
Maximum Vibration Does not exceed 8.2 ft/sec2
(2.5 m/sec2) at operator’s position Sound Power Level 86 dB @ 1m
Ambient Operating Range -20° F min
120° F max -29° C min 49° C max Ground Pressure/Wheel (Maximum) 59 psi 4.15 kg/cm2
Wheel Lug Nut Torque 150 lb-ft 203 Nm Maximum Wheel Load 2,975 lb 1,350 kg
Meets applicable requirements of ANSI A92.20-2018.
Allowable ambient temperature range: -20° F to 120° F (-29° C to 49°C).
Consult with MEC for operation outside of this range.
*Working Height adds 6 feet (2 m) to platform height.
**Weight may increase with certain options.
Specifications
Section 3 - Specifications

Page 5 34-J Diesel - Service & Parts Manual
December 2021
Bolt Torque Specification - American Standard
Use the following values to apply torque unless a specific torque value is called out for the part being
used.
American Standard Cap Screws
SAE Grade 5 8
Cap Screw
Size (inches) Torque Torque
Ft. Lbs Nm Ft. Lbs Nm
Min Max Min Max Min Max Min Max
1/4 - 20 6.25 7.25 8.5 10 8.25 9.5 11 13
1/4 - 28 8 9 11 12 10.5 12 14 16
5/16 - 18 14 15 19 20 18.5 20 25 27
5/16 - 24 17.5 19 12 26 23 25 31 34
3/8 - 16 26 28 35 38 35 37 47.5 50
3/8 - 24 31 34 42 46 41 45 55.5 61
7/16- 14 41 45 55.5 61 55 60 74.5 81
7/16 - 20 51 55 69 74.5 68 75 92 102
1/2 - 13 65 72 88 97.5 86 96 116 130
1/2 - 20 76 84 103 114 102 112 138 152
9/16 - 12 95 105 129 142 127 140 172 190
9/16 - 18 111 123 150 167 148 164 200 222
5/8 - 11 126 139 171 188 168 185 228 251
5/8 - 18 152 168 206 228 203 224 275 304
3/4 - 10 238 262 322 255 318 350 431 474
3/4 - 16 274 302 371 409 365 402 495 544
7/8 - 9 350 386 474 523 466 515 631 698
7/8 - 14 407 448 551 607 543 597 736 809
1- 8 537 592 728 802 716 790 970 1070
1 - 14 670 740 908 1003 894 987 1211 1137
Torque values apply to fasteners as received from the supplier, dry or when lubricated with
normal engine oil.
If special graphite grease, molydisulphide grease, or other extreme pressure lubricants are
used, these torque values do not apply.
Specific Torque Values for Selected Fasteners
Location Qty. Size Type Grade Torque (LB-FT)
Lug Nuts 36 9/16-18 NUT 8 135
Platform Mount To Rotator 8 M10x1.50 SHCS 12.9 60
Rotator Thru Bolt 1 3/4-10x9 HHCS 8 375
Rotator Thru Nut 1 3/4-10 NNYL 8
Platform Transition Bolt 4 M20x2.50 HHCS 10.9 250-270
Platform Transition Nut 4 M20x2.50 NNYL 10.9
Bolt Torque Specification - American Standard
Section 4 - Torque Specifications

Page 6 34-J Diesel - Service & Parts Manual
December 2021Section 4 - Torque Specifications
Bolt Torque Specification - Metric Standard
Use the following values to apply torque unless a specific torque value is called out for the part being
used
Metric Cap Screws
Metric Grade 8.8 10.9
Cap Screw Size
(Millimeters)
8.8
9.01
Torque Torque
Ft. Lbs Nm Ft. Lbs Nm
Min Max Min Max Min Max Min Max
M6 × 1.00 6 8 8 11 9 11 12 15
M8 × 1.25 16 20 21.5 27 23 27 31 36.5
M10 × 1.50 29 35 39 47 42 52 57 70
M12 × 1.75 52 62 70 84 75 91 102 123
M14 × 2.00 85 103 115 139 120 146 163 198
M16 × 2.50 130 158 176 214 176 216 238 293
M18 × 2.50 172 210 233 284 240 294 325 398
M20 × 2.50 247 301 335 408 343 426 465 577
M22 × 2.50 332 404 450 547 472 576 639 780
M24 × 3.00 423 517 573 700 599 732 812 992
M27 × 3.00 637 779 863 1055 898 1098 1217 1488
M30 × 3.00 872 1066 1181 1444 1224 1496 1658 2027
Torque values apply to fasteners as received from the supplier, dry or when lubricated with
normal engine oil.
If special graphite grease, molydisulphide grease, or other extreme pressure lubricants are
used, these torque values do not apply.

Page 7 34-J Diesel - Service & Parts Manual
December 2021Section 4 - Torque Specifications
Hydraulic Components Torque Table
Note: Always lubricate threads with clean hydraulic fluid prior to installation.
Use the following values to torque hydraulic components when a specific value is not available.
Always check for torque values in the following places before relying on the Hydraulic Components
Torque Table.
Parts drawings and service instructions in this manual.
Packaging and instruction sheets provided with new parts.
Instruction manuals provided by the manufacturer of the component being serviced.
Type: SAE Port Series Cartridge Poppet Fittings Hoses
Ft. lbs Nm Ft. lbs Nm In. lbs Nm
#4 N/A N/A N/A N/A 135 - 145 15 - 16
#6 N/A N/A 10 - 20 14 - 27 215 - 245 24 - 28
#8 25 - 30 31 - 41 25 - 30 34 - 41 430 - 470 49 - 53
#10 35 - 40 47 - 54 35 - 40 47 - 54 680 - 750 77 - 85
#12 85 - 90 115 - 122 85 - 90 115 - 122 950 - 1050 107 - 119
#16 130 - 140 176 - 190 130 - 140 176 - 190 1300 - 1368 147 - 155
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Page 8 34-J Diesel - Service & Parts Manual
December 2021
Boom Support
NEVER PERFORM WORK UNDER THE BOOM ASSEMBLY WITH THE
PLATFORM ELEVATED WITHOUT FIRST SUPPORTING THE BOOM
ASSEMBLY.
DO NOT work beneath the boom assembly with the platform elevated unless the boom assembly is
properly supported.
Use a sling and overhead hoist rated for 3 tons (2,700 kg) or more.
Wrap a sling under the outer end of the boom as shown below. Connect it to the overhead hoist, then
lift enough that the weight of the boom assembly is being supported by the hoist.
Art 5506
Boom Support
Section 5 - Boom Support

Page 9 34-J Diesel - Service & Parts Manual
December 2021
Hydraulic, Electrical and Total System
Hydraulic System
HYDRAULIC FLUID UNDER PRESSURE CAN PENETRATE AND BURN
SKIN, DAMAGE EYES, AND MAY CAUSE SERIOUS INJURY, BLINDNESS,
AND EVEN DEATH.
CORRECT LEAKS IMMEDIATELY.
Hydraulic fluid leaks under pressure may not always be visible. Check for
pin hole leaks with a piece of cardboard, not your hand.
Electrical System
To prevent damage to battery and/or electrical system:
Always disconnect the negative battery cable first.
Always connect the positive battery cable first.
•
•
When the negative cable is installed, a spark will occur if contact is made between the positive side
of the battery and a metal surface on the machine. This can cause electrical system damage, battery
explosion, and personal injury.
Total System
ENGINE COOLANT LEVEL MUST BE CHECKED ONLY AFTER ENGINE
HAS COOLED. IF RADIATOR CAP IS REMOVED WHILE THE COOLANT
IS AT NORMAL OPERATING TEMPERATURE, PRESSURE WITHIN THE
COOLANT SYSTEM WILL FORCE HOT LIQUID OUT THROUGH THE
FILLER OPENING AND MAY CAUSE SEVERE SCALDING.
Failure to perform preventive maintenance at recommended intervals
may result in the unit being operated with a defect that could result in
injury or death of the operator.
Immediately report to your supervisor any defect or malfunction.
Any defect shall be repaired prior to continued use of the aerial work
platform.
Inspection and maintenance should be performed by qualified personnel
familiar with the equipment.
Section 6 - Hydraulic, Electrical & Total System
Hydraulic, Electrical and Total System

Page 10 34-J Diesel - Service & Parts Manual
December 2021
Primary Machine Components
Chassis
Turn Table
Boom
Jib
Swing
Gate
Platform
Controls
Platform
Lift Gate
Controls Module
Hydraulic Tank
Base Controls
Fuel Tank
Engine Module
Engine
Art_5712
Primary Machine Components
Section 7 - Primary Machine Components

Page 11 34-J Diesel - Service & Parts Manual
December 2021
Emergency Systems and Procedures
IF THE CONTROL SYSTEM FAILS WHILE THE PLATFORM IS ELEVATED,
HAVE AN EXPERIENCED OPERATOR USE THE EMERGENCY LOWERING
PROCEDURE TO SAFELY LOWER THE PLATFORM.
DO NOT ATTEMPT TO CLIMB DOWN ELEVATING ASSEMBLY.
Emergency Stop
The machine is equipped with an EMERGENCY STOP switch on both control
panels.
Press the EMERGENCY STOP switch at any time to stop all machine
functions.
Turn switch clockwise to reset.
Selector Switch Set To Platform
Either switch will stop all machine functions.
Both switches must be reset or machine will not operate.
•
•
•
•
ART_3353
Selector Switch Is Set To Base
The upper controls are locked out.
The lower controls switch must be reset or the machine will not operate.
The machine will operate from the lower controls if the upper controls switch is tripped.
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Emergency Systems and Procedures
Section 8 - Emergency Systems and Procedures

Page 12 34-J Diesel - Service & Parts Manual
December 2021Section 8 - Emergency Systems and Procedures
Auxiliary Power System & Test
IF PRIMARY POWER FAILS WHILE THE PLATFORM IS ELEVATED, USE
THE AUXILIARY POWER SYSTEM TO SAFELY LOWER THE PLATFORM.
DO NOT CLIMB DOWN THE BOOM ASSEMBLY OR EXIT THE PLATFORM
WHILE ELEVATED.
ALWAYS CHECK OVER, UNDER AND AROUND THE MACHINE FOR
PERSONNEL, STRUCTURES AND OBSTRUCTIONS BEFORE ACTIVATING
ANY CONTROL FUNCTION AND CONTINUE TO WATCH FOR HAZARDS
WHILE OPERATING THE MACHINE
ART_4735
Base Controls
Platform Controls
Upper Auxiliary
Power Switch
Lower Auxiliary
Power Switch
Auxiliary
Power Switch
The Auxiliary Power System is used to lower the platform in case of primary power failure.
To lower the platform, activate the Auxiliary Power Switch to run the auxiliary hydraulic pump.
This function uses battery power from the battery to lower the platform.
Push and hold the Auxiliary Power Switch, then use the Boom Extend/Retract function to retract
the boom.
Continue to hold the Auxiliary Power Switch, then use the Boom Lift/Lower function to lower the
boom.
Note: The engine will turn off when theAuxiliary Power System is operated.
Note: The Auxiliary Power Switch serves as an enable switch. It is not necessary to use the primary
function enable switch.
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Page 13 34-J Diesel - Service & Parts Manual
December 2021
Lift and Support the Machine
DEATH OR SERIOUS PERSONAL INJURY MAY RESULT FROM THE USE
OF SUBSTANDARD LIFTING DEVICES AND/OR JACK STANDS. ENSURE
THAT ALL LIFTING DEVICES AND JACK STANDS ARE OF ADEQUATE
CAPACITY AND IN GOOD WORKING CONDITION BEFORE USE.
BE SURE THAT THE SURFACE BENEATH THE MACHINE IS CAPABLE OF
SUPPORTING THE JACK AND JACK STANDS.
REMOVE ALL MATERIAL, TOOLS AND PERSONNEL FROM THE
PLATFORM BEFORE LIFTING.
The following are needed to safely lift and support the machine;
A jack with a lifting capacity of five (5) tons or more.
Jack stands with a rating of five (5) tons or more.
To Raise The Machine
Move machine to a firm level surface capable of supporting the weight of the machine.
Chock the tires on the end of machine opposite the end to be raised.
If wheel is to be removed, break loose but do not remove lug nuts before raising the machine.
Position a jack at the end of the machine to be lifted, under a solid lifting point in the center of
the frame.
Raise the machine and place two (2) suitable jack stands under solid support points at the outer
ends of the frame.
Lower the machine to rest on the jack stands and inspect for stability.
To Lower The Machine
Tighten lug nuts to hold the wheel snug to the hub. Do not torque the lug nuts at this time.
Raise machine slightly and remove jack stands.
Lower the machine and remove the jack.
Tighten lug nuts to proper torque (Refer to Specifications).
Remove chocks.
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2.
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4.
5.
6.
1.
2.
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4.
5.
Lift and Support the Machine
Section 9 - Transporting and Lifting Instructions

Page 14 34-J Diesel - Service & Parts Manual
December 2021Section 9 - Transporting and Lifting Instructions
Transportation Instructions
Safety Information
This section is provided for reference and does not supersede any
government or company policy regarding the loading, transport or lifting
of MEC machinery.
Truck drivers are responsible for loading and securing machines, and
should be properly trained and authorized to operate MEC machinery.
Drivers are also responsible for selecting the correct and appropriate
trailer according to government regulations and company policy. Drivers
must ensure that the vehicle and chains are strong enough to hold the
weight of the machine (see the serial number plate for machine weight).
ONLY properly trained and qualified operators shall load and unload this
machine.
Free-wheel configuration for Winching or Towing.
RUNAWAY HAZARD!
After releasing the brakes there is nothing to stop machine travel.
Machine will roll freely on slopes.
ALWAYS chock the wheels before manually releasing the brakes.
The machine can be winched or towed short distances at speeds not to exceed 5 MPH (8 km/h).
Before towing or winching the machine, it is necessary to release the brakes. Reset the brakes after
towing or winching.
The machine can be winched or towed short distances at speeds not to exceed 5 MPH (8 km/h).
Before towing or winching the machine, it is necessary to release the brakes. Reset the brakes after
towing or winching.
Art 5598
Hand Pump
Pressure
Control
Valve
Release Valve
Disengage Brakes before Towing or Winching
Chock the wheels.
Push and hold the black button on the Brake Release
Valve.
Press the red button on the Hand Pump valve 8-10 times
until there is firm resistance and the brakes release.
Engage Brakes before Driving
Manually by pulling the black button out on the Brake
Release Valve, or
Automatically by engaging the drive function.
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Note: Brakes will reset automatically when drive function is activated.